Water resource shortage has become a serious threat to the national economic development and the people's living quality improvement. During coal mining, mine groundwater will be inevitably produced in a mine. In some mines, the annually discharged mine groundwater is as high as 2.2 billion tons, and 2 tons of waste water will be discharged once one ton of coal is mined on average. Thus, a great amount of valuable water resource is wasted. Furthermore, once the mine groundwater is discharged out, it will cause serious environment pollution to the surrounding environment.
For example, in the western areas of China, the coal resource is abundant while the water resource is deficient. The water shortage situation in mining areas and in surrounding regions is getting further worse, thus seriously restricting normal production of mining areas and being harmful to harmonious resource-environment development.
Currently, in the processing to mine groundwater, the mine groundwater is mainly pumped to the ground surface. Due to factors such as seasonality for water resource usage, the water resource is seriously wasted, thus causing unbalance for local water resource supply. Also, the processing of the mine groundwater suspended matter as well as water quality is performed mainly by discharging the mine water from underground to the ground surface, which tends to cause secondary pollution.
For protection to mine groundwater resource, several attempts have been made in China. For example, Wutongzhuang Mine of Fengfeng Corporation, in order to prevent and manage the harm to deep water and protect the mine groundwater, collected and processed the mine groundwater, and backfilled it to the Ordovician limestone aquifer. In addition, in some patent literatures such as “Mine water processing and mine water integrated processing device” (CN1884145), “Mine water processing technology by means of mine underground tunnel spaces” (CN101012091), “Coal mine groundwater purification processing device and method” (CN102336484A), “Mine water comprehensive processing and using technology” (CN101975087A), “Purification method for coal mine mined-out area mine groundwater” (CN1482078), solutions of filtering and purifying water by mined-out areas, processing mine water by a purification device using tunnel spaces, collecting and using mine water to process and protect mine water were proposed, respectively.
In the above methods, the mine water is used mainly by first collecting mine water to a water sump by an underground pump and piping and then transporting the water via discharging pipes to the ground surface for use. Two ways were provided: 1) collecting and then processing the mine groundwater in a mine, and then directly re-using the water in production underground in the mine; and 2) collecting the water and then transporting the same to the ground surface for processing and use. Both of these two ways, either processing underground after collecting, or processing on the ground surface, will pump mine water from the stratum spaces. In fact, this will cause mine groundwater run-off, resulting in continuous drop in water level and leading to the negative effect on the growth and recovery of the ecological environment.